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Octopus Server EUVDEUVD-2026-112580

| CVE-2026-118426 MEDIUM
Missing Authorization (CWE-862)
2026-10-29 Octopus GHSA-j7xx-fgfg-xff8
5.3
CVSS 4.0 · Vendor: Octopus
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Authenticate with low-privilege Octopus account
  2. Exploit
    Call LDAP user/group search endpoint
  3. Execution
    Missing authorization check bypassed
  4. Impact
    Enumerate directory users and groups

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Authorization checks on every request
MITRE ATT&CK

1 technique across 1 tactic: Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Exploitation requires two conditions both drawn from the description: (1) the Octopus Server instance must have the LDAP authentication provider enabled, and (2) the attacker must already be an authenticated user (CVSS PR:L), so this is not reachable by anonymous/unauthenticated actors. On instances using a different authentication provider or with LDAP disabled, the affected LDAP user-search and group-search functions are not applicable. No user interaction is required and the vector is network-reachable, but the authenticated-plus-LDAP-enabled requirement meaningfully limits the exposed population.

Impact

This is a moderate-severity information-disclosure/authorization flaw (CWE-862, Missing Authorization), not a critical issue. The vendor-supplied CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N) scores 5.3 and is internally consistent with the description: PR:L reflects that the actor is already an authenticated Octopus Server user, VC:L reflects limited confidentiality exposure (LDAP directory data returned via user/group search), and VI/VA:N reflect no integrity or availability impact. There is no CISA KEV listing and no EPSS score was supplied, so there is no signal of active or probable widespread exploitation; exploitation status is therefore 'no public exploit identified at time of analysis.' The only reference is the vendor's own advisory (sa2026-18), reported by Octopus, with a vuln.today Decision label of 'this_month' - consistent with a real-but-non-emergency patch priority rather than an act-now situation. The practical risk is bounded: an attacker must already hold valid credentials AND the LDAP authentication provider must be enabled. Where those hold, a low-privileged authenticated user can enumerate LDAP directory contents (users/groups) they were not authorized to query, which is useful for reconnaissance and lateral-movement planning but does not by itself grant code execution or privilege escalation.

Exploit ScenarioDerived

A low-privileged but authenticated Octopus Server user on an instance configured with the LDAP authentication provider invokes the LDAP user-search and LDAP group-search functions, which fail to enforce an authorization check. They harvest directory information (account names, group memberships) for reconnaissance to support further targeting. No public exploit code has been identified; only the vendor advisory is available.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).
Patch available 0.3% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 29, 2026

Missing authorization in Octopus Server allows any authenticated user to invoke the LDAP user-search and LDAP group-search functions when the LDAP authentication provider is enabled, allowing them to query LDAP user and group information through Octopus Server. The issue is rated CVSS 5.3 (CWE-862) and is limited to deployments using LDAP authentication; the supplied vector uses PR:L, so an attacker must already have an account. No public exploit was identified at time of analysis.

RemediationAI

Upgrade Octopus Server to a release listed as fixed in vendor advisory SA2026-18 (https://advisories.octopus.com/post/2026/sa2026-18); the input does not provide an exact fixed version, so the advisory's version matrix is authoritative. If an immediate upgrade is not possible, disabling the LDAP authentication provider removes the affected LDAP user-search and group-search path, at the cost of changing how users authenticate and losing LDAP-backed directory integration. No other vendor workaround is specified in the provided data, and no public exploit was identified at time of analysis.

Affected VersionsENISA

Octopus Server 2026.3.0 <2026.3.15909
Octopus Server 3.0.0 <2026.2.13487

Affected Packages

euvd octopus_server fix: 2026.2.13487, 2026.3.15909

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Octopus Server can delegate authentication and directory lookups to an LDAP authentication provider. In affected versions, the LDAP user-search and LDAP group-search operations lack an authorization check (CWE-862, Missing Authorization), so an authenticated user can call them directly rather than being restricted to administrative or otherwise privileged roles. The provided CVSS:4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N) and the independent CVSS:3.1 assessment both require a low-privileged authenticated account, and the description confines the issue to instances where LDAP authentication is enabled. The CPE entry is a wildcard match for octopus_deploy:octopus_server, so the version range must be taken from the vendor advisory rather than the CPE alone. The trigger is not described beyond the ability to call the LDAP search functions.

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Severity by source

Vendor (Octopus) PRIMARY 5.3 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
vuln.today AI 4.3 MEDIUM

Authenticated user abuses a missing authorization check over the network, so PR:L/AC:L/UI:N; only limited directory information is disclosed, so C:L and I/A:N.

3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (Octopus).

CVSS VectorVendor: Octopus

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Vulnerable system: Confidentiality
Low
Vulnerable system: Integrity
None
Vulnerable system: Availability
None
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

1
Patch available
Oct 29, 2026 - 03:00 EUVD

DescriptionCVE.org

In affected versions of Octopus Server with the LDAP authentication provider enabled, any authenticated user could call the LDAP user search and LDAP group search.

Threat Intelligence Overview

EPSS Score
0.3%
Top 81% exploitable
Prevalence
Medium
widely-used CI/CD deployment tool, common in enterprise DevOps but not universal
Social Media
1
Sightings
Data Quality
4 sources
Confidence: Medium

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity MEDIUM
CISA KEV No
Public POC No
EPSS 0.3%
Patch available Yes
Active threat No
Deciding rule
MEDIUM severity (CVSS 4.0-6.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

26
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +26
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.

CVE-2018-18850 HIGH POC
8.8 Oct 31

In Octopus Deploy 2018.8.0 through 2018.9.x before 2018.9.1, an authenticated user with permission to modify deployment

CVE-2019-11632 HIGH POC
8.1 May 01

In Octopus Deploy 2019.1.0 through 2019.3.1 and 2019.4.0 through 2019.4.5, an authenticated user with the VariableViewUn

CVE-2026-4881 MEDIUM POC
6.0 Jun 04

Server-level configuration changes can be made by any authenticated low-privilege user in Octopus Server through a speci

CVE-2022-2572 CRITICAL
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In affected versions of Octopus Server where access is managed by an external authentication provider, it was possible t

CVE-2022-2778 CRITICAL
9.8 Sep 30

In affected versions of Octopus Deploy it is possible to bypass rate limiting on login using null bytes. Rated critical

CVE-2018-11320 CRITICAL
9.8 May 21

In Octopus Deploy 2018.4.4 through 2018.5.1, Octopus variables that are sourced from the target do not have sensitive va

CVE-2026-0704 CRITICAL
9.1 Feb 25

Path traversal in Octopus Deploy allows removing files and file contents on the host through API manipulation. Enables d

CVE-2022-2782 CRITICAL
9.1 Oct 27

In affected versions of Octopus Server it is possible for a session token to be valid indefinitely due to improper valid

CVE-2026-92355 HIGH
8.7 Sep 16

Path traversal in Octopus Server allows an authenticated low-privilege user to overwrite arbitrary files on the server f

CVE-2026-101169 HIGH
8.7 Sep 29

Authenticated remote code execution in Octopus Server allows any user whose role grants permission to edit an Environmen

CVE-2026-102478 HIGH
8.7 Oct 07

Privilege escalation in Octopus Server lets an authenticated user who already holds permission to modify roles weaken a

CVE-2026-102488 HIGH
8.7 Oct 08

Incorrect authorization in Octopus Server causes the platform to evaluate multiple scoped permission assignments incorre

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